Re: [Intel-gfx] [PATCH v1 1/1] drm/i915/xe2lpd: alternate WA for underruns with PSR2 and FBC

[Jani Nikula <jani.nikula@linux.intel.com>]

On Fri, 03 Nov 2023, Vinod Govindapillai <vinod.govindapillai@intel.com> wrote:
> Implement the alternate WA for the underruns when both PSR2
> and FBC is enabled.

But we don't enable FBC when PSR2 is enabled, for display 12+.

See intel_fbc.c line 1200 or so.

BR,
Jani.


>
> Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_fbc.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
> index bde12fe62275..b9cd92a997cd 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbc.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbc.c
> @@ -608,6 +608,7 @@ static u32 ivb_dpfc_ctl(struct intel_fbc *fbc)
>  static void ivb_fbc_activate(struct intel_fbc *fbc)
>  {
>  	struct drm_i915_private *i915 = fbc->i915;
> +	u32 dpfc_ctl;
>  
>  	if (DISPLAY_VER(i915) >= 10)
>  		glk_fbc_program_cfb_stride(fbc);
> @@ -617,8 +618,17 @@ static void ivb_fbc_activate(struct intel_fbc *fbc)
>  	if (intel_gt_support_legacy_fencing(to_gt(i915)))
>  		snb_fbc_program_fence(fbc);
>  
> +	/*
> +	 * Alternate WA for HW bug with PSR2 + FBC.
> +	 * 1.Write FBC_CTL with Plane binding set correctly with FBC enable = 0
> +	 * 2.Write FBC_CTL with Plane binding set correctly with FBC enable = 1
> +	 */
> +	dpfc_ctl = ivb_dpfc_ctl(fbc);
> +	if (DISPLAY_VER(i915) >= 20)
> +		intel_de_write(i915, ILK_DPFC_CONTROL(fbc->id), dpfc_ctl);
> +
>  	intel_de_write(i915, ILK_DPFC_CONTROL(fbc->id),
> -		       DPFC_CTL_EN | ivb_dpfc_ctl(fbc));
> +		       DPFC_CTL_EN | dpfc_ctl);
>  }
>  
>  static bool ivb_fbc_is_compressing(struct intel_fbc *fbc)

-- 
Jani Nikula, Intel